The present invention relates to a method and apparatus for controlling, in a production line in which a plurality of products are processed successively by using a plurality of processing apparatus, the progress of processing for each of the products on a lot-by-lot basis. More particularly, the present invention achieves a remarkable effect if it is applied to an LSI production/prototyping line in which it is necessary to change a processing priority for each of the lots, control the progress of processing for each of the lots, or perform the activation/deactivation or maintenance of the processing apparatus in view of the progress of processing for each of the lots.
In a conventional apparatus for controlling the progress of product processing, a processing priority for a specified product has been changed or the progress of processing for the specified product has been controlled in accordance with a deviation of the progress of processing for the specified product from a processing schedule therefor.
Referring to FIG. 38, the conventional apparatus for controlling the progress of product processing will be described.
FIG. 38 is a block diagram of the conventional apparatus for controlling the progress of product processing, which comprises: processing state control means 1 for controlling the states of processing for a plurality of products in each of processing apparatus composing a production line; processing progress sensing means 2 for sensing the progress of processing for a specified product; processing schedule extracting means 3 for obtaining a processing schedule for the specified product; and processing priority changing means 4 for changing the processing priority for the specified product based on the result of a comparison between the progress of processing for the specified product and the processing schedule for the specified product.
Specifically, the processing state control means 1 acquires the processing initiation time and processing completion time of each of the products in each of the processing apparatus composing the production line and registers the acquired processing initiation time and processing completion time of each of the products as product processing state data in a table or the like on a computer memory. The processing progress sensing means 2 senses, based on the product processing state data, the progress of processing for the specified product. The processing schedule extracting means 3 extracts, from processing schedules for the plurality of products stored preliminarily in the table or the like on the computer memory, the processing schedule for the specified product. The processing priority changing means 4 compares the sensed progress of processing for the specified product with the processing schedule for the specified product. If the progress of processing for the specified product is behind the schedule, the processing priority changing means 4 increases the processing priority for the specified product such that the specified product is processed with a higher priority than the other products. If the progress of processing for the specified product is ahead of the schedule, on the other hand, the processing priority changing means 4 lowers the processing priority for the specified product.
However, since the conventional apparatus for controlling the progress of product processing controls processing for the specified product such that it proceeds in accordance with the schedule by properly changing the processing priority for the specified product based on the progress of processing for the specified product, as described above, the following problems are encountered.
(1) Even if a related product which should be processed in association with the progress of processing for a specified product is present, the progress of processing for the specified product cannot be controlled in accordance with the progress of processing for the related product. If the processing for the related product proceeds ahead of the schedule, e.g., the processing for the specified product is not allowed to proceed ahead of the schedule. In particular, since it is common to check the mid-fabrication characteristics of a specified lot and then determine whether or not a processing condition for another lot (related lot) or the progress of processing therefor is proper during the production/prototyping of an LSI product, it is a challenge of great importance to control the progress of processing for the specified lot in accordance with the progress of processing for the related lot. Nevertheless, the challenge has not been solved by the conventional apparatus for controlling the progress of product processing. The importance of the challenge further increases as LSIs are miniaturized increasingly since an increasing number of processing conditions should be examined or checked in lines for producing or prototyping the LSIs.
(2) Although it is necessary to perform the activation, deactivation, or maintenance of a processing apparatus in accordance with the progress of processing for products, an instruction to effect activation, deactivation, or maintenance cannot be given to the processing apparatus without interrupting product processing.
(3) Even if there is a group of related products which is at least one product to be processed in association with processing for the specified product, the processing priority for the specified product cannot be determined to correspond to the number of products composing the group of related products or to the processing priority for the group of related products. In particular, since it is common to check the mid-fabrication characteristics of a specified lot and then determine a processing condition for the group of related lots during the production/prototyping of an LSI product, it is a challenge of great importance to determine a processing priority for the specified lot such that it corresponds to the number of lots composing the group of related lots or to the processing priority for the group of related lots in order to complete the LSI product in a shorter period of time. Nevertheless, the challenge cannot be solved by the conventional apparatus for controlling the progress of product processing.